Lubricant



Patented Aug. 13, 1940 LUBMCAN T Erich M. Steifen, Berlin, Germany,assignor, by mesne assignments, of three-fourths to Tide WaterAssociated Oil Company, New York,

N. i[., a, corporation of Delaware No Drawing. Application September 15,1936,

Serial No. 100,826. 1940 12 Claims.

This invention relates to lubricants, and more particularly is concernedwith certain synthetic compositions of matter formed by the catalyticconversion of rubber and which are effective to 6 impart valuable anddesired characteristics to lubricating oils when blended therewith.

in my co-pending application, Serial No. 683,169, now issued as PatentNo. 2,142,219 of January 3, 1939, filed August 1 1933, for Lubricants,it is shown that the treatment of rubber material with a catalyst suchas anhydrous alumium chloride produces stable conversion products whichare exceedingly valuable in the production of high grade lubricatingoils. Therein, it is also shown that such a catalytic conversion ofrubber advantageously may be efiected in the presence of chlorinatedhydrocarbons, such as chlorinated mineral oil, selected chlorinatedmineral oil fractions, or specific halogenated hydrocarbons of whichethylene dichloride may be cited as a convenient example. In theco-pending application, Serial No. 26,616, filed June 14, 1935, by mejointly with John E. Schott, now issued at ?atent No. 2,142,220 ofJanuary 3, 1939, there is disclosed and claimed broadly the improvementin such compositions and their preparation which flows from the presenceduring the rubber conversion reaction of unsaturated compounds suchasthe olefines, di-olefines, and those hydrocarcons of an aromaticnature which are similarly reactive in the presence of anhydrousaluminum chloride to form more stable conversion products. Polymergasoline or fractions thereof may be used as additional material in thepresence of which the anhydrous aluminum chloride conversion of rubbermay be effected.

The synthetic compositions of matter produced in the foregoingoperations proved generally valuable as blending agents for hydrocarbonoils,

4" and exhibited particular utility in the production of lubricatingcompositions having desired properties of low pour point and highviscosity index.

It is an important object of the present invention to provideimprovements in the formation of 45 compositions of this character tothe end that the production thereof may be facilitated. 'A

particular object resides in the use of an improved catalyst.

I have now discovered that th general reaction comprising the anhydrousaluminum chloride conversion of rubber material, whether per se or inthe presence of added material such as chlorinated hydrocarbons,unsaturated and like hydrocarbons generally, and polymer gasolinespecifically, may be simplified in operation and rendered Renewed.lanuary 24,

more readily controllable by effecting the said reaction by means of amixed catalystin place of straight anhydrous aluminum chloride.

The mixed catalyst which I use in my improved catalytic rubberconversion operation comprises 5 an intimate mixture of anhydrousaluminum chloride with finely divided or comminuted metal, in particulariron preferably in powder-like or dust-like form. The iron apparentlyneed not be of extreme chemical purity, that is normal proportions ofimpurities such as oxides or other metals may be present, but such otherelements as are contained in iron intended for use in my mixed catalystshould be limited in total quantity to amounts ordinarily regarded asimpurities, for example not substantially in excess of 5% -10% based onthe weight of the iron.

Insofar as I am aware, the use of a mixed catalyst comprising anhydrousaluminum chloride and a metal in my rubber conversion reaction does notextend broadly to all metals. Thus, I have found by experiment thatfinely divided metallic aluminum or a mixture of finely divided metalliccopper and metallic-Zinc are not desirable ior use according to theinvention since the 25 presence of these metals seems to have the effectI of unduly reducing the effectiveness of the rubber conversion productsas addition agents for mineral hydrocarbon oils; the products resultingfrom conversions of rubber in these latter instances being markedlyinferior in pour point lowering effect upon mineral lubricating oils.

In further more specific illustration of the practice of the presentinvention, the following examples of the production of syntheticcompositions having pour point lowering properties are given. It will beunderstood, of course, that the particularized steps, proportions, andreacting ingredients other than catalyst are given by way ofillustration and not by way of limitation since the discovery underlyingthe present invention has proved applicable to various modifications ofthe general rubber conversion reaction broadly disclosed and claimed inmy aforesaid co-pendlng application, Serial No. 683,169 new issued asPatent No. 2,142,219 of January 3, 1939.

Example I I Rubber (40 grams in finely divided state), solvent naphtha(approximately 500 ccs.) and poly- 5 mm gasoline (750 cos. of a 62.7" A.P. I. product having a boiling'range of 90 F. to 437 F. with a contentof unsaturates and aromatics totalling over 50% and produced bythermal'pclymerization of cracked gases) are intimatelyadmixed 55 withagitation and heated at about 160 F. for suflicient time to occasionperfect gel formation. In this case, the vessel in which the rubber gelis formed preferably communicates with a condenser for receiving andcollecting the lighter fractions present which boil below 160 F. andtherefore pass overhead. This is unnecessary, of couse, when the variousingredients all boil above the temperature at which the mixture isheated.

Meanwhile, the mixed catalyst of the invention is prepared by intimatelymixing 18 grams of anhydrous aluminum chloride and 20 grams of finelydivided metallic iron. With the rubbersolvent gel still at the formationtemperature of about 160 F., a 7-- gram portion of the mixed catalyst isadded thereto with agitation, whereupon an immediate reaction isevidenced by liquifaction of the gel and an increase in the reactionmixture temperature to 178 F. without further external application ofheat. Within a few minutes, a further portion of catalyst in the amountof 4 grams is added and continued progress of the reaction is evidencedby an increase in temperature to 194 F. After an additional few minutesof reaction at this temperature, the remaining portion of the catalystcomprising 27 grams is added to the reaction mixture which thereaftershortly rises in temperature to 221 F. Thereaction is complete within 1to 1% hours from the time of first catalyst addition; and the mixturethen is cooled to between F. and F., Washed with an alcoholic causticsolution (1 part ethyl alcohol-1 part 25% aq. NaOH solution), andallowed to settle for a short period. A bright, clear, red solution isobtained which, after separation from a relatively small amount ofsludge sedimentation, is reduced by steam distillation to yield 94 gramsof a yellow-red resin having pronounced utility as an addition orblending agent for mineral lubricating oils. Thus, 1% by weight added tocertain oils gave the following results:

Example [I Rubber (40 grams in finely divided state), solvent naphtha(approximately 500 ccs.), polymer gasoline (350 cos. of a fractionboiling above 200 F., the original being the same as in Example I) andcresol (1 cc.) are intimately admixed with agitation and heated to aboutF. for sufficient time to occasion perfect gel formation.

Meanwhile, the mixed catalyst of the invention is prepared by intimatelymixing 18 grams ofanhydrous aluminum chloride and 18 grams of finelydivided metallic iron. With the rubbersolvent gel still at the formationtemperature of about 175 F., an 18 gram portion (i. e., one-half of thetotal used) of the mixed catalyst is added thereto with agitation, nofurther external application of heat. An immediate reaction is evidencedby liquefaction of the gel and an increase in the reaction mixturetemperature to 194 F. Within about 10 minutes, the remaining 18 gramportion of the mixed catalyst is added and continued reaction effects anincrease in reaction mixture temperature to 221 F. The overall time forcompletion of the desired conversion reactions is somewhat under 1 hourfrom the time of first catalyst addition; and the mixture then is cooledto about 120 F.-125 F., washed with an alcoholic caustic solution (1part ethyl alcohol- 1 part 25% NaOH solution), and allowed to settle fora short period. A bright, clear, red solution is obtained which, afterseparation from a relatively small amount of settled sludge, is reducedby steam distillation to yield 86 grams of a red resin having pronouncedutility as an addition or blending agent for mineral lubricating oils.

Thus, 1% by weight added to certain oils gave the following results:

Various advantages attend the practice of my present invention ascompared with methods using straight anhydrous aluminum chloride as acatalyst for the rubber conversion reaction. Smaller proportions ofaluminum chloride relative to polymerizable ingredients may be used, andthis is desirable to the end of minimizin possibilities of excessivecatalytic action resultin in partial depolymerization of the desiredhigh molecular weight compounds first formed. The

reaction is fully self-sustaining with respect to heat requirements,thus enhancing its practical aspect. At the same time, overall reactionperiod is short which is a factor of value in large scale production.

In the foregoing illustrative examples, equal or nearly equalproportions by weight of anhydrous aluminum chloride and of finelydivided metallic iron are used. The invention is not limited to theseproportions, however, both larger and smaller amounts of iron beinguseful. In general, it is desirable to use minimum amounts of aluminumchloride, but optimum proportions will depend, among other things, uponsuch factors as the initial temperature at which catalyst is introducedinto the reaction mixture, the quantity, character, and relativeproportions of the reaction'mixture ingredients including rubber, andthe like, for any given set of conditions.

' Likewise, it is not necessary that the rubber conversion be effectedin the presence of polymer gasoline, the invention being practiced withequal utility in the straight conversion of rubber per se, or in theconversion of rubber in the presence of other materials such aschlorinated hydrocarbons, or those hydrocarbons, of a generallyunsaturated nature which have a capacity for undergoing chemical changeto more stable form whenreactively contacted with a catalyst having theefiect of anhydrous aluminum chloride.

In the matter of catalyst addition according to the present invention, Ihave found it beneficial to practice a portion-wise introduction intothe reaction mixture in successive steps, as is illustrated in theexamples given above. This method ture during reactionfbut it is notessential to successful operation that this exact practice be observed.3

I claim:

1. The method of preparing synthetic compositions useful for blendingwith lubricating oils, which comprises subjecting rubber material to theaction of anhydrous aluminum chloride in the presence of metallic ironunder conditions effective to produce conversion products.

2. The method of preparing synthetic compositionsuseful for blendingwith lubricating oils, which comprises subjecting rubber material andchlorinated hydrocarbons to the action of anhydrous aluminum chloride inthe presence of metallic iron under conditions effective to produceconversion products.

3. The method of preparing synthetic compo- I sitions useful forblending with lubricating oils,

which comprises subjecting rubber material together with at leastoneother hydrocarbon to v the action of anhydrous aluminum chloride inaluminum chloride in the presence of metallic iron under conditionseffective toproduce conversion products. v

5. Stable, synthetic compositions characterized by the property ofreducing the pour point-of wax-containing hydrocarbon oils when blendedtherewith comprising products obtained by sub-. jecting rubber materialto the action of anhydrous aluminum chloride in the presence of metalliciron under conditions effective to produce conversion products.

6. Stable, synthetic compositions characterized by the property ofreducing the pour point of wax-containing hydrocarbon oils when blendedtherewith comprising products obtained by subjecting rubber materialtogether with other bydrocarbons, at least one of which is characterizedby a capacity for undergoing chemical change to more stable form whenreactively contacted with aluminum chloride, to the action of anhydrousaluminum chloride in the presence of metallic iron under conditionsefiective to produce conversion products.

7 Stable, synthetic compositions characterized by the property ofreducing the pour point of wax-containing hydrocarbon oils when blendedtherewith comprising products obtained by subjecting rubber material andchlorinated hydrocarbons to the action of anhydrous aluminum chloride inthe presence of metallic iron under conditions effective to produceconversion products. 8. Stable, synthetic compositions characterized bythe property of reducing the pour point of wax-containing hydrocarbonoils when blended therewith comprising products obtained bysubjectingrubber material and polymer gasoline to the action of anhydrous aluminumchloride in the presence of metallic iron under conditions efiective toproduce conversion products.

9.' An improved lubricant having as a major constituent a viscoushydrocarbon oil and containing, in relatively minor proportion based onthe amount of said oil, a synthetic composition characterized by itseffectiveness in lowering the pour point of wax-containing hydrocarbonoils and comprising the product obtained by subjecting rubber to theaction of anhydrous aluminum chloride in the presence of 'metallic ironunder conditions eifective to produce conversion products.

10. The method of preparing lubricants, which comprises subjectingrubber material to the action of anhydrous aluminum chloride in thepresence of metallic iron under conditions effective to produceconversion products, recovering stable,

synthetic compositions having pour point lowering properties, andblendiiig such compositions with viscous hydrocarbon oil in relativelyminor proportion.

v 11. The method'of preparing synthetic compo-- sitions useful forblending with lubricating oils,

which comprises subjecting rubber material to the action of a catalystof the type exemplified by anhydrous aluminum chloride,'in the presenceof

